Lead solder indicator and method

• US 20050285274A1
• Filed: 06/29/2004
• Published: 12/29/2005
• Est. Priority Date: 06/29/2004
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Inventors: Koschmieder, Thomas H., Burnette, Terry E.
• Granted Patent: US 7,074,627 B2
• Time in Patent Office: Days
• US Class Current: 257/772
• CPC Class Codes: H01L 22/34 Circuits for electrically characterising or monitoring manufacturing processes, e. g. whole test die, wafers filled with test structures, on-board-devices incorporated on each die, process control monitors or pad structures thereof, devices in scribe line switching, multiplexing, gating devices G01R19/25; process control with lithography, e.g. dose control, G03F7/20; structures for alignment control by optical means G03F7/70633
• CPC Class Codes: H01L 2224/1181 Cleaning, e.g. oxide removal step, desmearing
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/8121 using a reflow oven
• CPC Class Codes: H01L 2224/81815 Reflow soldering
• CPC Class Codes: H01L 23/49816 Spherical bumps on the substrate for external connection, e.g. ball grid arrays [BGA]
• CPC Class Codes: H01L 24/81 using a bump connector
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/01046 Palladium [Pd]
• CPC Class Codes: H01L 2924/01047 Silver [Ag]
• CPC Class Codes: H01L 2924/01049 Indium [In]
• CPC Class Codes: H01L 2924/0105 Tin [Sn]
• CPC Class Codes: H01L 2924/01051 Antimony [Sb]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/01082 Lead [Pb]
• CPC Class Codes: H01L 2924/01322 Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/014 Solder alloys
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H05K 1/0269 : for visual or optical inspection
• CPC Class Codes: H05K 2203/161 : Using chemical substances, e.g. colored or fluorescent, for facilitating optical or visual inspection
• CPC Class Codes: H05K 2203/163 : Monitoring a manufacturing process
• CPC Class Codes: H05K 3/3463 : Solder compositions in relation to features of the printed circuit board or the mounting process
• CPC Class Codes: H05K 3/3489 : Composition of fluxes; Methods of application thereof; Other methods of activating the contact surfaces

Abstract

A solder system includes a lead (Pb) indicator and a solder flux. A method for forming a semiconductor device includes providing a carrier, applying the solder system to the carrier, coupling the terminal to the carrier via the solder system, melting the solder system to attach the terminal to the carrier and form a completed semiconductor device, and determining if the completed semiconductor device has a different predetermined property from the solder system.

Claims

1. A solder system for coupling a terminal to a carrier, wherein the solder system comprises:

a lead (Pb) indicator for detecting a presence of lead (Pb); and

a solder flux to serve as a carrier for the lead (Pb) indicator.

2. The solder system of claim 1, wherein the solder system comprises a coating on the carrier.

3. The solder system of claim 2, wherein the carrier is selected from the group consisting of a printed circuit board and a ball grid array substrate.

4. The solder system of claim 1, wherein the solder system further comprises a conductive material.

5. The solder system of claim 1, wherein the conductive material comprises a solder powder.

6. The solder of claim 5, wherein the conductive material is devoid of lead (Pb).

7. The solder of claim 5, wherein the conductive material comprises lead (Pb).

8. The solder system of claim 1, wherein the lead (Pb) indicator comprises a visual lead (Pb) indicator.

9. The solder system of claim 8, wherein the visual lead (Pb) indicator comprises an acid.

10. The solder system of claim 9, wherein the visual lead (Pb) indicator comprises rhodizonic acid.

11. The solder system of claim 8, wherein the visual lead (Pb) indicator comprises sodium sulfide.

12. The solder system of claim 1, wherein the terminal comprises a conductive structure selected from the group consisting of leads, balls, pins, end caps, and pads.

13. A method for forming a semiconductor device, the method comprising:

providing a carrier;

applying a solder system to the carrier, wherein the solder system comprises;

a lead (Pb) indicator; and

a solder flux; and

coupling a terminal to the carrier via the solder system;

melting the solder system to attach the terminal to the carrier and form a completed semiconductor device;

determining if the completed semiconductor device has a different predetermined property from the solder system.

14. The method of claim 13, wherein determining further comprises visually inspecting the completed semiconductor device.

15. The method of claim 13, wherein applying the solder system further comprises applying a solder system, wherein the solder system further comprises a conductive material.

16. The method of claim 13, wherein applying the solder system further comprises applying a solder system, wherein the solder flux serves as a carrier for the lead (Pb) indicator.

17. The method of claim 13, wherein applying the solder system further comprises applying a solder system, wherein the lead (Pb) indicator further comprises a visual lead (Pb) indicator.

18. The method of claim 13, wherein applying the solder system further comprises applying the solder system as a coating on the carrier.

19. The method of claim 13, wherein applying the solder system further comprises applying the solder system, wherein the lead (Pb) indicator comprises rhodizonic acid.

20. The method of claim 13, wherein applying the solder system further comprises applying the solder system, wherein the lead (Pb) indicator comprises sodium sulfide.

21. The method of claim 13, wherein determining further comprises determining if the completed semiconductor device has a color different from the solder system.